Selector-switch.



6.185111111111151. SELECTOR SWITCH.

ARPLICATION FILED MAR. I4 1913.

1,1 84,1 62. Patented May 23, 1916.

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G. A. BETULANDER.

SELECTUR SWITCH.

APPLlcATwN mio MAR.14, 1913.

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UNITED STATES PATENT OFFICE.

GOTTHILF ANSGARIUS BETULANDER, OF SDER-TRNS VILLASTAD, SWEDEN, ASSIGNORTO THE BETULANDER AUTOMATIC TELEPHONE COMPANY, LIMITED, OF LONDON,

ENGLAND.

SELECTOR-SWITCH.

Application led March 14, 1913.

To @ZZ whom t 'may concern Be it known that I, GOTTHILF ANsGARrUSBETULANDER, a subject of the King of Sweden, and resident of SdertrnsVillastad, in the Kingdom of Sweden, have invented certain new anduseful Improvements in Selector-Switches, of which the following is aspecification, reference being had therein to the accompanying drawings.

The invention relates to selector switches provided with individual,electro-magnetic driving devices. In selectors of that class theselective shifting movement is usually effected directly by means of anelectro-magnetic step-by-step acting mechanism, while the restoring ofthe selector is effected by spring force or by gravity. Such selectorsmay be reliable, it is true, when operated at moderate speeds. At highspeeds, however, they lose in security of service owing to the fact thata relatively great mass is to be aocelerated at every advancement, sothat impulses of current may be lost. Furthermore, great shifting speedsmay cause inadmissible stresses prejudically affecting the adjustmentand reducing the length of life of the selector. In order to attaingreat shifting speeds without the said disadvantage one has tried toprovide means for imparting to the line contacts a continuous selectivemovement, as is in itself well known already long ago. For instance, ithas been proposed to use a solenoid in such a manner that the linecontacts are shifted continuously by the movable core of the solenoidbeing attracted and are restored to normal position by sp 1ing force.However, such a selector has several inconvenient features. In someforms of solenoid selectors, for instance, it is necessary to keep thesolenoid or an electro-magnet current carrying during the conversationwhich causes a considerable loss of current. This said disadvantage maybe overcome, it is true, in other constructions but the selector isthereby made more complicated or less reliable in operation.

A simple and reliable selector is obtained according to this inventionby reversing the driving conditions in the selectors in the class inquestion, so that the selective movement is effected by means of springforce or gravity while the restoring of the selectorl is effected bydirect action of the electro-magnetic driving device. By so constructingthe Specification of Letters Patent.

Patented May 23, 1916.

Serial No. 754,273.

selector no power is, obviously, consumed in keeping the selector inshifted position as the line contacts may be stopped against the actionof the spring force or gravity or by cutting off the motive power. Theconsumpt1on of electric power occurs only at the restoring of the linecontacts to normal position and corresponds closely to the amount ofpower necessary for the shifting of the selector. Furthermore, in aselector according to .this invention an ordinary electromagneticstep-by-step acting device may be used as the source of power of theselector, while in a selector where the continuous selective movement isto be effected directly by the electro-magnetic driving device, asolenoid is inevitable which is more complicated and more expensive thanan ordinary electro-magnet. A step-by-step acting driving device is somuch the more advantageous as the above mentioned disadvantages ofstepby-step mechanisms are entirely omitted in selectors according tothe present invention inasmuch as the restoring operation may beperformed at a lower rate than the selective operation. In addition, byusing spring force or gravity the motive power for the selectivemovement will be more uniform, whereas the tractive power of a solenoidvaries during the movement of the core.

The invention refers especially to pre-selectors or similar selectorsfor automatic telephone exchanges but may for instance also be appliedto group-selectors. A groupselector may, advantageously, be so arrangedthat the line contacts are first shifted in known manner step by step inone direction to select a certain group of lines and then, according tothis invention, are moved continuously in a direction perpendicular tothe direction first mentioned to hunt for a. disengaged line of the saidgroup.

The invention is illustrated in the accompanying drawings, which showtwo forms of the same. Figure l shows schematically a preselector withrectilinear shifting movement and Fig. 2 a pre-selector with rotatingmovement. Fig. 3 is a side view of a part of the selector, shown in Fig.2.

The pre-selector shown in Fig. 1 is arranged as follows. In a stationaryplate l two studs 2 are fixed, to which a frame 3 is pivoted. Aconnecting rod 6 is slidably mounted in the two shanks 4, 5 of the saidframe, which rod carries at its top end contact springs 7 and 8,insulated from the rod, and a spring 10, provided with a roller 9,whichis held in constant contact with the corresponding part of the contactfield of the selector. T he object of the said roller is to examine. ifthe lines of the field are engaged or not engaged. Two electro-magnets11 and 12 (the working electro-magnet and the auxiliary electro-magnetrespectively) are fixed to the frame 3. 'fhe electro-magnet (11) firstmentioned alone effects the adjustment of the connecting rod 6 and incoperation with the other electro-magnet (12) the returning of the same.The armature 13 of the electro-ma gnet 11 is pivoted to the frame 3 andcarries at its free end a lever-arm 14, which acted upon by a spring 15fixed to the shank 4, keeps the armature 13 in raised position and apawl 16, pivoted to the lower end of the lever-arm 14, in engagementwith the teeth 17 of the connecting rod 6. To the lower end of the leverarm 14 is fixed a pin 18, which slides along an oblique surface 19 onthe electro-magnet 11. The armature 20 of the electro-magnet 12, whichhas the shape of a bell crank lever and is pivoted at 21, is forced by aspring 22 against the lower end of the lever arm 14 and is provided witha pawl 24, acted upon by a spring 23. The movement of the pawl 24 awavfrom the top part of the armature 20 is limited by a screw 86 extendingfreely through the pawl and in screw-threaded engagement with thearmature 20, the head of which thus limits the movement in the saiddirection, so that, as the armature 13 is attracted by the electromagnet11, the pawl 16 as well as the pawl 24 are brought out of engagementwith the teeth 17 cf the connecting rod 6 by the spring 22. To the lowerpart of the plate 1 is fixed an electro-magnet 25 (the disconnectingelectromagnet) the armature 26 of which is pivoted to the shank 5 andprovided at its free end with a pawl 27, which acted upon by a spring 28fixed to the armature 26, is held in engagement with the teeth 29,provided on the lower end of the connecting rod 6. A, screw 30 isprovided on the shank The armature 26, when attracted by theelectromagnet 25, strikes the said screw, before it arrives to thesurface of the pole of the electro-magnet, which results in the frame 3and the parts carried by the same being moved by the armature 26 and thecontact springs 7 and 8 being brought out of contact with thecorresponding` contact-field. The movement of the frame 3 is limited bya pin 31 fixed in the plate 1. The frame 3 is moved in the oppositedirection by a spring 32, fixed in the frame 3 and the plate 1, and thismovement is limited by a pin 33, fixed in the plate 1. In the positiondetermined by the pin 33 the contact springs 7 and 8 are in contact withthe corresponding contact field. To the outer end of the shank 5 isfixed an angular piece 34, to the lower end of which is pivoted ananchor escapement 35, which co'perates with teeth 36 on the connectingrod 6 for causing the said rod, when released and moved downward by itsweight to fall at a speed as uniform as possible.

On the shank 5 is provided a group of contact springs 37, 33, 39, 40,41, 42, 43, 44, acted upon by the armature 20, while on the shank 4 areprovided a group of contact springs 45, 46, 47, 48, acted upon by thearmature 13, and a group of contact springs 49, 50, 51, 52, acted uponby the connecting rod 6. In addition to the said groups of contactsprings a group of contact springs 53, 54, 55 is provided, which isacted upon by the frame 3. y

The pre-selector operates in the following manner. As the subscribercauses his number switch to operate in order to provide a connection forconversation one 56 of the line branches is connected with earth. Inthis manner an impulse of current is sent through line 56, line 68,contact ,spring 39, contact spring 40, line 58, the winding of theelectro` magnet 11, wire 59 and battery 75, which results in thearmature 13 being attracted and the pawls 16 and 24 being brought out ofengagement with the teeth 17 of the connecting rod 6 by the spring 22,owing to the fact thatl the pin 18 on the arm 14 slides along theslanting surface 19. At the same time the contact spring 46 has beenbrought into contact with the contact spring 45s-1nd 1 an impulse ofcurrent has been sent through contact spring 45, contact spring 46, line60, contact spring 50, contact spring 49, line 61, contact spring 38,contact spring 37, line 62, line 63, the winding of the electro-magnet25, line 64, line 65 and battery 75. At the same time the armature 26 isthus attracted and the pawl 27 is brought out of engagement with theteeth 29 of the connecting rod 6, which results in the latter startingits downward movement, the frame 3 is tilted and the contact springs 7and 8 are brought out of contact with the corresponding contact field.The rod 6 now falls down rapidly and it continues to move until theroller 9 of the contact spring 10 has found the testing'wire of anunoccupied groupselector- If the group-selector is occupied, i. e., thetesting wire of the same connected with earth, current passes throughcontact spring 10, line 66, contact spring 54, contact spring (thecontact at 55 islnow broken), line 67, line 61, contact spring 38,contact spring 37, line 62, line 63, the winding of the electro-magnet25, line 64, line 65, and battery 75. Consequently, the armature 26 ofthe electro-magnet remains attracted, i. e., the pawl of the same isheld out of engagement with the teeth of the connecting rod. It is to beobserved, that the first impulse of current through the electro-magnet11 must continue for such a long period, that the rod 6, if necessary,can fall down for such a distance, as corresponds to the distancebetween the first and the last lines of the contact field.

As soon as the contact roller 9 has found an iin-occupied line, the saidconnection is interrupted, and the armature 26 releases and prevents byits pawl 27 t-he connecting rod 6 from continuing its movement just inthe position, which corresponds to the unoccupied line of thegroup-selector, and at the same time the contact springs 7 and 8 arebrought into contact with corresponding contact fields.

The selector is brought to its initial posiwhich results in the contactspring 42 being brought into contact with the contact springs 43 and 44and the contact spring 40 being brought into contact with the contactspring 41. As the connecting rod has been brought out of its upperposition of rest, the contact spring 51 has been brought into contactwith the contact spring 52, which is connected with earth, as shown. Inthis manner. a flow of current is effected through contact spring 52,contact spring 51, line 72, contact spring 42, partially through contactspring 43, line 7 the winding of the electro-magnet l2 line 71, line 65,and battery 75, partially through contact spring 44, line 63, thewinding of the electro-magnet 25, line 64, line and battery 75. Thearmature 26 is thus attracted. so that the contact springs 7 and S arebrought out of contact with the corresponding contact field in themanner described above. and the armature 26 as well as the armature 20are now held in attracted position. until the connecting rod 6 hasreached its upper position of rest and broken the contact 51. Theshifting back (returning) of the rod 6 is effected in such manner thatan intermittent current is sent from earth through a rota ry interrupter7 (i, line 74, contact spring 41. contact spring 40, line 58, thewinding of the electro-magnet 11, line 59 battery 75, so that thearmature is attracted repeatedly and by means of the lever drum 14 andpawl 16 moves step by step the connecting rod to its upper position ofrest, in which the contact 51 is broken, which results in the armatures20 and 26 being released and the contact 40, 41 being broken andconsequently the intermittent current through the electro-magnet 11interrupted. At the same time the contact springs 7 and 8 haye beenbrought into contact with the corresponding contact fields through thereleasing of the armature 26.

ln the form of the pre-selector shown in Figs. 2 and a segment 7 8provided with teeth 77 is substituted for the connecting rod 6, whichsegment together with the springs 7, 8 and 10 fixed to the segment andinsulated from the same is swung by a spring 79 over the contact field.The said segment 78 and the springs. provided on the same. together withan arm SO, which is fixed to the segment and in the free end of which astop screw S1 is provided, are fixed on a longitudinally slidable shaft82, which is acted upon by the armature 26 of the electromagnet 25against the action of a spring 83 in such manner, that, as the saidarmature is attracted the contact springs 7 and 8 are brought out ofcontact with the contact field.

and the stop screw S1 is brought out ofen-l gagement with recesses S4provided in a plate The contact spring 10 is held in constant contactwith the contact field. The electrical operations are identical withthese described above with reference to the selector shown in F ig. 1.The mechanical operations are as follows.

As the subscriber causes his number switch to operate, the armature 13is first attracted and the pawls 16 and 24 are. brought out ofengagement with the teeth 77 of the segment 7S by the spring 22.. Owingto the fact that the contact 45, 46 is thereby closed, theelectro-magnet 25 is excited and its armature 26 attracted. which, asbefore stated, results in the contact springs 7 and S being brought outof' contact with the contact field and the stop screw S1 being broughtout of engagement with the recesses S4. The segment 78 and the partsprovided on the same are now swung rapidly by the spring 79, until thetesting spring 10, in the same manner as stated above with reference tothe selector shown in Fig. 1 finds the line of an unoccupiedgroup-selector. in which moment the flow of' current through theelectro-magnet 25 is interrupted and the segment together with thecontact springs are locked by the screw S1. engaging the correspondingrecess 84, at the same time as the contact springs 7 and 8 are broughtinto contact with the contact field.

The returning of' the selector to its initial position is effected inthe manner described above by an impulse of current being sent throughthe line branch 57 and the electromagnet 12. so that its armature 2O isattracted and in consequence thereof a flow of current is sent throughthe winding of the electro-magnet 12 as well as the winding of theelectro-1nagnet 25. which flow of current does not cease until thesprings 7, S and 10 of' the selector have been fully returned throughthe intermittent flow of current through the rotating interrupter 76 andthe lOt.

electro-magnet l1 and the repeated attracting of the armature 13resulting therefrom, and the contact 52, 53 has been broken.

Having now described my invention, what l claim as new and desire tosecure by Letters Patent is:

1. A selector switch having movable line contacts, a moving deviceadapted, upon being released, to eii`ect a continuous selective movementof the line contacts, an electromagnetic driving device adapted torestore tl e line contacts to normal position, a catching device, anelectro-magnet operating said catching device to stop the line contactsin different positions and means operated by `the same electro-magnet tomove the line contacts out of contact with the contact field.

2. A. selector switch having movable line contacts supported by a memberslidably `iournaled in a movable guide and adapted to be moved` bygravity, a catching device adapted to stop said member in dilferentpositions and an electro-magnet operating said catching device torelease the slidable member and at the same time operating said guide tomove the line contacts out of contact with the contact field.

3. A selector switch comprising` a rockertrame, a slidable membercarried by the rocher-frame, a line selector and line contacts on saidslidable member and movable therewith, a movable member carried byl saidframe for retnrninO' said slidable member to its normal position andnormally held in engagement therewith, a lock member on saidrocker-trame and adapted to engage the slidable member to lock thelatter in different positions, means for disengaging said movable andlool; members from said slidable member' to allow the latter to make aselective movement and to actuate said lock member to rock said rockerframe so that said line contacts will be moved out of the paths of theircontact points, means for operatingsaid loch member to loc t saidslidable member in position upon the selec- 'tion of said selector andto rock the rocker frame to bring the line contacts in engagement withtheir selected contact points, means for actuating said movable memberto restore said slidable member to normal position and to render saidlock member ineffective, said disengagement means being adapted tooperate said lock member to roclr the rocker-frame, during saidrestoring operation to bring the line contacts out of the path of theirrespective contact points, and a second lock member coperating with saidmovable member during the restoration of said slidable member, said lockmeans being adapted to lock said slidable member in normal positionafter said restoring operation.

d. A selector switch comprising a slidable member, a line selector andline contacts on said slidable member and movable therewith, a movablemember for restoring said slidable member to its normal position andnormally held in engagement therewith, a loch member adapted to engagethe slidable member to lock the latter in different positions, means fordisengaging said movable member and said lock member from enga gementwith said slidable member to allow the latter to make a selectivemovement, means for operating said lock member to lock said slidablemember in position upon selection of said selector, means for actuatingsaid movable member to restore said slidable member to normal positionand to render said locking member ineffective during said restoringoperation, and a second lock member coperating with said movable memberduring the restoration of said slidable member.

5. A selector switch having movable line contacts supported by a memberslidably journaled in a movable guide and adapted to be moved bygravity, a catching device adapted to stop said member in differentpositions and an electro-magnet adapted to' put the catching device outof action thereby releasing` the slidable member and at the same timeoperating to move the line contacts out of Contact with the contactfield.

6. A selector switch comprising, a rockerframe, a slidable membercarried by the rocker-frame, a line selector and line contacts on saidslidable member and movable therewith, a movable member carried by saidframe for returning said slidable member to its normal positionl andnormally held in engagement therewith, a lock member on saidrocker-trame and adapted to engage the slidable member to lock thelatter in different positions, means for disengaging said movable andlock members from said slidable member to allow the latter to make aselective movement and to actuate said lock member to rock saidrocker-frame so that said line contacts will be moved out of the pathsof their Contact points, means for operating said loch member to locksaid slidable member in position upon the selection of said selector andto rock the rocker-frame to bringthe line contacts in engagement 7. Aselector switch, comprising, a slidable member, a line selector and linecontacts on said slidable member and movable therewith, a movable memberfor restoring said slidable member to its normal position and normallyheld in engagement therewith, a lock member adapted to engage theslidable member to lock the latter in different positions, means fordisengaging said movable member and said lock member from engagementwith said slidable member to allow the latter to make a selectivemovement, means for operatingr said lock member to lock said slidablemember in position upon selection of said selector, means for actuatingsaid movable member to restore said slidable member to normal positionand to render said locking member ineffective during said restoringoperation, and a second lock member cooperatingr with said movablemember during the restoration of said slidable member.

In Witness whereof, I have hereunto signed my name in the presence oftwo subscribing witnesses.

GOTTHILF ANSGARIUS BETULANDER.

Witnesses GRETA PRIEN, ROBERT APLEGREN.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents. Washington, D. C.

